Hi all,
May I know what is the role of acids (HCl, H2SO4, Acetic acid, phosphoric acid, Oxalic acid and nitric acid) in removing lignin/ cellulose/ hemicellulose in lignocellulosic biomass?
If we use HCl what it will do for Lignocellulosic biomass
If we use H2SO4 what it will do for Lignocellulosic biomass
If we use Acetic acid what it will do for Lignocellulosic biomass
If we use Phosphoric acid what it will do for Lignocellulosic biomass
If we use Oxalic acid what it will do for Lignocellulosic biomass
If we use above acids for steam pretreated biomass what will happen
and
If we use sodium hypochlorate what it will do for Lignocellulosic biomass
If we use sodium sulphite what it will do for Lignocellulosic biomass
Please let me know in detail
Thank you
Some (xylan) of lignocellulosic components are easily hydrolyzed than cellulose or lignin. Removal of xylan in lignocellulosic biomass brought the separation of complex structure to easily access the cellulose degrading enzymes.
phosphoric acid is different story, which can convert the crystalline cellulose to amorphous, which is good for enzymatic saccharification.
chlorine-related chemicals can selectively remove the lignin as bleaching, which afford cellulase accessible to cellulose in lignocellulosic biomass.
agree with shin.
As indicated in our paper, acid is not effective for subsequent hydrolysis. the role of h2so4 is de-xylan rather than delignification. Many studies try to explain what is the major reason for enhanced hydrolysis, but parameters such as CrI, delignification,xylan content, SSA etc. are always changed at the same time. so we still do not know the exact reason.
For more, please refer to my paper.
Lignocelluloses are complex structure and important structural components of the cell walls of plants, in which polymeric carbohydrates, namely cellulose and hemicellulose, are tightly bound to the lignin. The role of acid treatment is to break the polymeric bond (delignification) by altering or removal of structural and prepositional impediments to hydrolysis. It has been found that production of value-added chemicals from monomers are easie than polymers, pretreatment of polymeric molecules required to give their respective monomer followed by its further dehydration, oxidation,hydrogenation etc. into high valued chemicals and fuels.
For more details, you may go through following papers:
Journal of Catalysis 288 (2012) 8–15
Catalysis Science & Technology 2 (2012), 2025-2036.
I looked at loblolly pine and acetic acid added to water in hydrothermal carbonization (230 C). It tends to remove hemicelluloses and cellulose to a certain extent, rather than lignin. A link to the paper is at joanlynam.com.
I agree with all answers written above. I just want to add that you need to consider two important things: type of lignocellulosic biomass and temperature of reaction. Namely, depending of biomass type and its composition acids might differently affect its polymers. Also depending of temperature different polymers will be affected by acid, i.e. cellulose should stay preserved on temperatures below 200 degrees of Celsius.
I used HCl for sugar beet pretreatment. More about it you can see in
Biomass and Bioenergy, 47:387–394
Dilute sulfuric acid is best for pretreatment of lignocellulosic biomass. SEM and XRD sowed that lignin and wax was removed successfully and crystallinity was decreased. See the attached paper.
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